We propose to develop and perform new, critically-needed population- demographic and population-genetic analyses, make population management recommendations, and create research-information-systems, for the U.S. research chimpanzee population. Some of this work will utilize a unique research resource a "studbook" dataset we have already assembled on the origin/parentage an institutional move history of 5,821 captive chimpanzees, 2,700 now living and 3,121 of their ancestors and predecessors, held historically by a total of over 233 institutions worldwide (142 currently report information on live animals to us). Other aspects of this work involving identification of subpopulations of individuals with specific research histories, will require expansion of this dataset. This research and development effort is in recognition of the unique vital national needs identified in the objectives of the U.S.National Chimpanzee Plan of PHS: -insure a stable supply of chimpanzees for essential biomedical and behavioral research without depleting the captive population of these animals. -perpetuate the chimpanzee population in the United States through the reproduction and maintenance of physically healthy and behaviorally normal animals for future generations. Carrying out these objectives presents challenges encountered with no other animal model. Our research on this population is itself a model- for the kind of approach increasingly necessary for handling a vital, scarce, expensive, threatened, long-lived and self-sustaining captive population of research primates. We will carry out research on population demography and genetics, studying the planned decades-long transition to a fully captive-bred self-sustaining population, and analyzing mating options for maximum retention of genetic diversity. We will also develop the first-ever analysis of the research-history-subpopulations within the captive chimpanzee population, developing information systems tracking the multiple research assignments of the animals themselves, and analyze the demographics and genetics of the sub-populations defined by these histories. This information bears directly on some critical topics, such as "What is the genetic diversity of the chimpanzee population likely to be used for HIV candidate vaccine testing?, and "How many chimpanzees are available for HIV research over the next 3 years?" Results of general interest will be published and all will be made available to NCRR - responsible for population management at NIH, and the inter-agency Animal Model Committee (IAMC), responsible for allocation and assignment of individual chimpanzees to specific research protocols, an to the individual facilities.